Vacuum system

[MinorMatt]

It should get up to about 15PSI

[CCCars]

Hi Matt, that was just full revs in neutral so no load on the engine, will do a road test to see what I get under load, but at least it looks like the new sensor is working correctly.
Two things come to mind, either my turbo has had it or the waste gate could be seized open preventing the turbo from developing full boost pressure, what do you think, I've tried to move the waste gate linkage without success assuming it was stuck in the closed position but maybe it's wedged partly open?
Thanks
Graham

[MinorMatt]

Well, when mine had a hoofing great hole in the inlet tract and couldn't make more than about 2 PSI it didn't throw any faults.

Personally I think your issue is electronic

[CCCars]

Sorry it's been a while but I spent a lot of time eradicating the tin worm before the dreaded MOT test, fortunately successfully as it passed with no advisories! So back to the boost issue or lack of it.
Had a good look around the engine bay and failed to locate any leaks on the air side from the turbo to the inlet so decided to take a look inside the inlet manifold and ports with my endoscope to check for fouling but whilst it was pretty dirty in there nothing that could be called a blockage.
While I had the manifolding open decided it would be a good time to check the valve clearances and found them all to be wide of the mark each needed as much as 3/4 turn on the adjustment screws to reduce the gaps to the correct settings resulting in a slight increase in performance and I think an improvement in economy although I haven't checked that properly yet.
I think my next step wiill be to to drop the exhaust off the turbo and see what it feels like, still sure it's mechanical as the boost pressure is being correctly measured by the boost pressure sensor checked by Forscan against my pressure gauge so without the correct boost the fuelling is being held back by the electronics to prevent smoke.
Weather not looking good for a few days so not sure when I'll get on this next step, when I do I'll let you know what I find.
Graham

[CCCars]

OK exposed the turbo and found a couple of things, shaft movement normal for a turbo of this size, no sign of blade contact with casing at either end, waste gate was seized but freed up with a good dose of penetrating oil and gentle persuasion, one of the hose clips on the outlet air hose was faulty and wouldn't tighten probably allowing charge air to escape, air filter was quite dirty so will be replaced.
Running light saw 5 psi on my gauge will test again with Forscan once I have a new air filter in place.
Graham